May 14, 1997
The Moon has changed phase thousands of times since the beginning of the cosmos, but only once did it shine on the night you arrived.
Hale-Bopp's Fickle Ion Tail
Birthday · May 14, 1997
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published May 14, 1997. Credit: A. Dimai, D. Ghirardo and R. Volcan (Col Druscie Obs., ACC). A publication-date match, not a photo taken on your date. Independent of NASA.
What's happening to Comet Hale-Bopp's blue ion tail? The comet's ion tail is fluctuating more rapidly as it passes a region of changing solar wind. As the comet passes from north to south, it crosses the plane of the Sun's equator, where the solar magnetic field changes direction. Ions from the solar wind, which cause Comet Hale-Bopp's ion tail, act unpredictably here. Therefore, Comet Hale-Bopp's ion tale may show unusual structure or even a disconnection - where the tail appears to break off and then reestablish itself later. The above picture, taken April 30th, indeed shows unusual structure in the blue ion tail.
Image credit: A. Dimai, D. Ghirardo and R. Volcan (Col Druscie Obs., ACC)